Relationship between maternal vitamins B2 and B6 status and the levels of these vitamins in milk at different stages of lactation. A study in a low-income group of Indian women

Abstract

Riboflavin and vitamin B6 status of mothers from a low-income group were assessed by erythrocyte glutathione reductase activation and erythrocyte aspartate aminotransferase activation tests respectively, at different stages of lactation. Levels of these vitamins in milk were also measured. The majority of the women had biochemical evidence of vitamins B2 and B6 deficiency. There was a bizarre reduction in erythrocyte glutathione reductase activation from 6 to 30 d post partum. Levels of riboflavin in milk were in general satisfactory, but vitamin B6 levels were lower than the values reported from developed countries. Clear-cut correlations between the enzymatic indices of vitamin status evaluation and milk levels of the corresponding vitamins were not apparent.

PIP: Riboflavin and vitamin B6 status of low-income mothers in Hyderabad, India, were assessed by erythrocyte glutathione reductase activation and erythrocyte aspartate aminotransferase activation tests, respectively, at different stages of lactation. Levels of these vitamins in milk also were measured. The 134 lactating women, who attended a maternal and child care clinic in a government hospital, were divided according to the duration of lactation into the following 6 groups: less than 5 days (Group I), 6-30 days (Group II), 1-6 months (Group III), 7-12 months (Group IV), 13-18 months (Group V), and more than 18 months (Group VI). 6 women had been using oral contraceptives (OCs) for 3-6 months (Group VII). Since OCs are not prescribed before 8 months of lactation, the lactational status of the OC users was comparable to that of the women in groups IV or V. Except for the pariurient mothers (Group I) who delivered in the hospital, the remainder of the women came to the hospital for routine pediatric care or contraceptive advice. Most women had had a frugal breakfast and had nursed their infants 2 hours prior to the sampling of blood and milk. 10 ml samples of foremilk (5 ml from each breast) were collected by manual expression. Samples of venous blood were draw after collecting the milk. Correlations between the maternal vitamin status and milk vitamin concentration were assessed by Pearson's correlation coefficient and frequency distribution. The majority of the women had biochemical evidence of riboflavin and pyridoxine deficiency, the incidence of the former being greater than the latter. Prolonged lactation did not worsen the vitamin status. Group II women showed a reduction in erythrocyte glutathione reductase activity (EGR-AC) values suggesting better riboflavin status than the other groups. A similar trend was not seen with regard to pyridoxal phosphate. Milk riboflavin concentration was similar in all the groups except Group II where the levels were significantly higher. Milk pyridoxine concentration increased 3-4 fold after 1 month of lactation and continued to be at that level beyond 18 months. There was no correlation between the maternal riboflavin and milk riboflavin status or maternal pyridoxine and milk pyridoxine status. The higher milk riboflavin concentration among the Group II women was seen regardless of the women's riboflavin status in that group. OC-treated women did not show any significant deviations from women not using OCs.